Biology Unit 2 Study Packet

non enclosed membranes

not all membranes are enclosed some examples are ribosomes and cytoskeletons

organelles in animal cell

nucleus, mitochondria, ribosomes, ER, golgi apparatus

cryo-EM

specimens are frozen rapidly to lock molecules in a rigid state, beam is passed through sample

surface/volume ratio

important for the nutrient exchange in/out of cell

first endosymbiotic event

eukaryotic cell engulfed aerobic bacterium making the mitochondrion

second endosymbiotic event

eukaryotic cell engulfed photosynthetic cyanobacterium creating the chloroplast

microtubules

hollow, large/thick; maintain cell shape, cell motility, and organelle movements

microfilaments

2 intertwined strands of actin; muscle contractions; and cytoplasmic streaming

tight junctions

establish a barrier that prevents leakage of extracellular fluid across cells

desmosomes

attach muscle cells to each other

gap junctions

give cytoplasmic channels from one cell to another, creates pores for ions, sugars, and amino acids

plasmodesmata

junction only found in plants

how hydrophilic proteins survive

the transmembrane segments are hydrophobic the hydrophilic parts also face the aqueous environment and there are peripheral membrane proteins

ion pump

membrane protein pump that moves ions across membrane

benefits of pumps and cotransport

pumps create electrochemical gradients and regulate cell volume while cotransport recycles energy and brings in nutrients without extra work

metabolic pathway

series of reactions that occur in a cell where the product of one reaction become reactant for the next

G

measure of amount of usable energy that can do work

free energy G

in catabolism free energy is released G is net negative; in anabolism it requires free energy so G is net positive

activation energy

the minimum amount of energy required for chem reactions, an enzyme lowers activation energy; an enzyme doesnt affect or change free energy

temperature and ph

two factors that affect enzyme action

cellular respiration type

catabolic reaction because it involves the breakdown of glucose into simpler molecules like CO2 and H2O and it releases energy

redox reactions

they are chemical reactions that transfer electrons between molecules

NAD+

electron carrier molecule that grabs bonds when glucose is broken

glycolysis

cuts into pyruvates acid glucose takes place in cytoplasm

krebs cycle

breaks down glucose to produce energy through metabolic pathways takes place in mitochondrion

oxidative phosphorylation

inorganic phosphate is transferred to adp to make atp to do work in mitochondrion

phosphorylation

adding a phosphate group to a molecule

acetyl CoA

acetyl group with a coenzyme it links glycolysis to the krebs cycle

atp synthase function

to synthesize atp to adp and inorganic phosphate through energy from proton gradient

reflection; absorption; transmission

when light photons/wavelengths meets matter these three things can occur; absorption drives photosynthesis

carbon fixation

inorganic CO2 is fixed with organic molecules that a plant can use

reduction

carbon molecules produced reduce to form high energy G3P

regeneration of co2

some G3P are used to regenerate RuBP

role of rubisco

catalyzes carbon fixation which is the first step to calvin cycle

NADPH in calvin cycle

it comes in during the reduction phase to photophosphorylate G3P to form 1,3 BPG